apache high cpu load on high traffic

 
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Operating Systems Linux Red Hat apache high cpu load on high traffic
# 1  
Old 09-30-2011
apache high cpu load on high traffic

i have a Intel Quad Core Xeon X3440 (4 x 2.53GHz, 8MB Cache, Hyper Threaded) with 16gig and 1tb harddrive with a 1gb port and my apache is causing my cpu to go up to 100% on all four cores heres my http.config

Code:
<IfModule prefork.c>
StartServers 10
MinSpareServers 10
MaxSpareServers 15
ServerLimit 1000
MaxClients 1000
MaxRequestsPerChild 5000
</IfModule>

<IfModule worker.c>
StartServers 35
MaxClients 200
MinSpareThreads 30
MaxSpareThreads 305 
ThreadsPerChild 255
MaxRequestsPerChild 0
</IfModule>

KeepAlive On

#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 800

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 2

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Last edited by radoulov; 09-30-2011 at 05:04 PM..
# 2  
Old 09-30-2011
there are many things you need to check, if your traffic usage ( in case of correct configuration ) isnt bigger than your server resource then:

1) you need to turn off KeepAlive
2) decrease MaxRequestsPerChild to 30
3) decrease Timeout if its bigger than 90seconds
4) check your sysctl.conf or use this pre-configured sysctl :
Code:
#Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Disables packet forwarding
net.ipv4.ip_forward=0

# Disables IP source routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.lo.accept_source_route = 0
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# Enable IP spoofing protection, turn on source route verification
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# Disable ICMP Redirect Acceptance
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.lo.accept_redirects = 0
net.ipv4.conf.eth0.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0

# Enable Log Spoofed Packets, Source Routed Packets, Redirect Packets
net.ipv4.conf.all.log_martians = 0
net.ipv4.conf.lo.log_martians = 0
net.ipv4.conf.eth0.log_martians = 0

# Disables IP source routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.lo.accept_source_route = 0
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# Enable IP spoofing protection, turn on source route verification
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.lo.rp_filter = 1
net.ipv4.conf.eth0.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# Disable ICMP Redirect Acceptance
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.lo.accept_redirects = 0
net.ipv4.conf.eth0.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0

# Disables the magic-sysrq key
kernel.sysrq = 0

# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 15

# Decrease the time default value for tcp_keepalive_time connection
net.ipv4.tcp_keepalive_time = 1800

# Turn off the tcp_window_scaling
net.ipv4.tcp_window_scaling = 0

# Turn off the tcp_sack
net.ipv4.tcp_sack = 0

# Turn off the tcp_timestamps
net.ipv4.tcp_timestamps = 0

# Enable TCP SYN Cookie Protection
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 3

# Enable ignoring broadcasts request
net.ipv4.icmp_echo_ignore_broadcasts = 1

# Enable bad error message Protection
net.ipv4.icmp_ignore_bogus_error_responses = 1

# Log Spoofed Packets, Source Routed Packets, Redirect Packets
net.ipv4.conf.all.log_martians = 1

# Increases the size of the socket queue (effectively, q0).
net.ipv4.tcp_max_syn_backlog = 1024

# Increase the tcp-time-wait buckets pool size
net.ipv4.tcp_max_tw_buckets = 1440000

# Allowed local port range
net.ipv4.ip_local_port_range = 16384 65536

net.ipv4.netfilter.ip_conntrack_max = 196605000


vm.dirty_background_ratio = 20
vm.dirty_ratio = 60

#reduce the number of time_wait connections
#these 3 lines can reduce your time_wait count by several hundred percent.
#however you should not use the following lines in a NATed configuration.
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 30

vm.swappiness=0

then run:
Code:
sysctl -p

5) check .htaccess of websites, sometimes they are using much cpu
6) check whether you are not under attack , use mod_security , mod_evasive , firewall like csf , etc...
7) check enabled modules , and exclude unnecessaries.
8) if your websites are running on php and your apache compiled with mod_suphp/phpSUEXEC/mod_fcgi/ ,etc they are 4 times slower than mod_php , switch to mod_php
9) use caches like eAccelerator , xcache , ...

finally, the information you gave isnt much that we rely on to help you resolve the problem, google for optimizing apache to find more on this.
This User Gave Thanks to ieth0 For This Post:
# 3  
Old 09-30-2011
i have memcached installed and when i get a rush of traffic it still maxes out the cores noo im not underattck these are actual visitors i also did all the edits you told me to thanks alot Smilie
# 4  
Old 10-01-2011
What's "a rush of traffic"? How big is it? 10 users? 10,000? If you're using HTTPS, the encryption/decryption is CPU-intensive, so a lot of users could very well peg your CPUs.
# 5  
Old 10-01-2011
load

no the load only would be 200-400 users at once heres my top when i get those users Image
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